This invention relates to the regulation of polynucleotide transcription and/or expression. More specifically, this invention relates to polynucleotide regulatory sequences isolated from plants that are capable of initiating and driving the transcription of polynucleotides, and the use of such regulatory sequences in the modification of transcription of endogenous and/or heterologous polynucleotides and production of polypeptides. Polypeptide sequences are also disclosed.
Gene expression is regulated, in part, by the cellular processes involved in transcription. During transcription, a single-stranded RNA complementary to the DNA sequence to be transcribed is formed by the action of RNA polymerases. Initiation of transcription in eucaryotic cells is regulated by complex interactions between cis-acting DNA motifs, located within the gene to be transcribed, and trans-acting protein factors. Among the cis-acting regulatory regions are sequences of DNA, termed promoters, to which RNA polymerase is first bound, either directly or indirectly. As used herein, the term xe2x80x9cpromoterxe2x80x9d refers to the 5xe2x80x2 untranslated region of a gene that is associated with transcription and which generally includes a transcription start site. Other cis-acting DNA motifs, such as enhancers, may be situated further up- and/or down-stream from the initiation site.
Both promoters and enhancers are generally composed of several discrete, often redundant elements, each of which may be recognized by one or more trans-acting regulatory proteins, known as transcription factors. Promoters generally comprise both proximal and more distant elements. For example, the so-called TATA box, which is important for the binding of regulatory proteins, is generally found about 25 basepairs upstream from the initiation site. The so-called CAAT box is generally found about 75 basepairs upstream of the initiation site. Promoters generally contain between about 100 and 1000 nucleotides, although longer promoter sequences are possible.
For the development of transgenic plants, constitutive promoters that drive strong transgene expression are preferred. Currently, the only available constitutive plant promoter that is widely used is derived from Cauliflower Mosaic Virus. Furthermore, there exists a need for plant-derived promoters for use in transgenic food plants due to public conceptions regarding the use of viral promoters. Few gymnosperm promoters have been cloned and those derived from angiosperms have been found to function poorly in gymnosperms. There thus remains a need in the art for polynucleotide promoter regions isolated from plants for use in modulating transcription and expression of polynucleotides in transgenic plants.
Briefly, isolated polynucleotide regulatory sequences from eucalyptus and pine that are involved in the regulation of gene expression are disclosed, together with methods for the use of such polynucleotide regulatory regions in the modification of expression of endogenous and/or heterologous polynucleotides in transgenic plants. In particular, the present invention provides polynucleotide promoter sequences from 5xe2x80x2 untranslated, or non-coding, regions of plant genes that initiate and regulate transcription of polynucleotides placed under their control, together with isolated polynucleotides comprising such promoter sequences.
In a first aspect, the present invention provides isolated polynucleotide sequences comprising a polynucleotide selected from the group consisting of: (a) sequences recited in SEQ ID NO: 1-14, 20, 22-62, 81-86 and 88-120; (b) complements of the sequences recited in SEQ ID NO: 1-14, 20, 22-62, 81-86 and 88-120; (c) reverse complements of the sequences recited in SEQ ID NO: 1-14, 20, 22-62, 81-86 and 88-120; (d) reverse sequences of the sequences recited. in SEQ ID NO: 1-14, 20, 22-62, 81-86 and 88-120; (e) sequences having either 40%, 60%, 75or 90% identical nucleotides, as defined herein, to a sequence of (a)-(d); probes and primers corresponding to the sequences set out in SEQ ID NO: 1-14, 20, 22-62, 81-86 and 88-120; polynucleotides comprising at least a specified number of contiguous residues of any of the polynucleotides identified as SEQ ID NO: 1-14, 20, 22-62, 81-86 and 88-120; and extended sequences comprising portions of the sequences set out in SEQ ID NO: 1-14, 20, 22-62, 81-86 and 88-120; all of which are referred to herein as xe2x80x9cpolynucleotides of the present invention.xe2x80x9d The present invention also provides isolated polypeptide sequences identified in the attached Sequence Listing as SEQ ID NO: 63-80 and 87; polypeptide variants of those sequences; and polypeptides comprising the isolated polypeptide sequences and variants of those sequences.
In another aspect, the present invention provides genetic constructs comprising a polynucleotide of the present invention, either alone, or in combination with one or more additional polynucleotides of the present invention, or in combination with one or more known polynucleotides, together with cells and target organisms comprising such constructs.
In a related aspect, the present invention provides genetic constructs comprising, in the 5xe2x80x2-3xe2x80x2 direction, a polynucleotide promoter sequence of the present invention, a polynucleotide to be transcribed, and a gene termination sequence. The polynucleotide to be transcribed may comprise an open reading frame of a polynucleotide that encodes a polypeptide of interest, or it may be a non-coding, or untranslated, region of a polynucleotide of interest. The open reading frame may be orientated in either a sense or antisense direction. Preferably, the gene termination sequence is functional in a host plant. Most preferably, the gene termination sequence is that of the gene of interest, but others generally used in the art, such as the Agrobacterium tumefaciens nopalin synthase terminator may be usefully employed in the present invention. The genetic construct may further include a marker for the identification of transformed cells.
In a further aspect, transgenic plant cells comprising the genetic constructs of the present invention are provided, together with organisms, such as plants, comprising such transgenic cells, and fruits, seeds and other products, derivatives, or progeny of such plants. Propagules of the inventive transgenic plants are included in the present invention. As used herein, the word xe2x80x9cpropagulexe2x80x9d means any part of a plant that may be used in reproduction or propagation, sexual or asexual, including cuttings.
Plant varieties, particularly registerable plant varieties according to Plant Breeders"" Rights, may be excluded from the present invention. A plant need not be considered a xe2x80x9cplant varietyxe2x80x9d simply because it contains stably within its genome a transgene, introduced into a cell of the plant or an ancestor thereof.
In yet another aspect, methods for modifying gene expression in a target organism, such as a plant, are provided, such methods including stably incorporating into the genome of the organism a genetic construct of the present invention. In a preferred embodiment, the target organism is a plant, more preferably a woody plant, most preferably selected from the group consisting of eucalyptus and pine species, most preferably from the group consisting of Eucalyptus grandis and Pinus radiata. 
In another aspect, methods for producing a target organism, such as a plant, having modified polypeptide expression are provided, such methods comprising transforming a plant cell with a genetic construct of the present invention to provide a transgenic cell, and cultivating the transgenic cell under conditions conducive to regeneration and mature plant growth.
In other aspects, methods for identifying a gene responsible for a desired function or phenotype are provided, the methods comprising transforming a plant cell with a genetic construct comprising a polynucleotide promoter sequence of the present invention operably linked to a polynucleotide to be tested, cultivating the plant cell under conditions conducive to regeneration and mature plant growth to provide a transgenic plant; and comparing the phenotype of the transgenic plant with the phenotype of non-transformed, or wild-type, plants.
In yet a further aspect, the present invention provides isolated polynucleotides that encode ubiquitin. In specific embodiments, the isolated polynucleotides comprise a polynucleotide selected from the group consisting of: (a) sequences recited in SEQ ID NO: 1 and 34; (b) complements of the sequences recited in SEQ ID NO: 1 and 34; (c) reverse complements of the sequences recited in SEQ ID NO: 1 and 34; (d) reverse sequences of the sequence recited in SEQ ID NO: 1 and 34; and (e) sequences having either 40%, 60%, 75% or 90% identical nucleotides, as defined herein, to a sequence of (a)-(d). Polypeptides encoded by such polynucleotides are also provided, together with genetic constructs comprising such polynucleotides, and host cells and transgenic organisms, for example plants, transformed with such genetic constructs. In specific embodiments, such polypeptides comprise a sequence provided in SEQ ID NO: 80 or 67.
In yet further aspects, the present invention provides isolated polynucleotides comprising the DNA sequence of SEQ ID NO: 21, or a complement, reverse complement or variant of SEQ ID NO: 21, together with genetic constructs comprising such polynucleotides and cells transformed with such sequences. As discussed below, removal of the sequence of SEQ ID NO: 21 from a polynucleotide that comprises the sequence of SEQ ID NO: 21 may enhance expression of the polynucleotide. Conversely, the inclusion of the sequence of SEQ ID NO: 21 in a genetic construct comprising a polynucleotide of interest may decrease expression of the polynucleotide.
The above-mentioned and additional features of the present invention and the manner of obtaining them will become apparent, and the invention will be best understood by reference to the following more detailed description. All references disclosed herein are hereby incorporated by reference in their entirety as if each was incorporated individually.